The second Advanced Extremely High Frequency satellite, AEHF 2, is prepared for launch atop a United Launch Alliance Atlas 5 rocket from Cape Canaveral Air Force Station in Florida.

CAPE CANAVERAL, Florida -- The launch of an Atlas V rocket carrying a U.S. Air Force satellite was scrubbed today for technical reasons. The rocket, built by United Launch Alliance in Decatur, Alabama, will try for a Friday launch.

The rocket was carrying an Air Force "Advanced Extremely High Frequency-2" satellite. The $1 billion satellite is designed to provide the president and military leaders secure communications during wartime. The launch was scrubbed because a required flow of helium from ground support to a compartment on the vehicle was interrupted.

Ground control will try again Friday between 1:42 p.m. and 4:442 CDT to launch the rocket from Space Launch Complex-41 at Cape Canaveral Air Force Station. Weather conditions are 80 percent favorable.